


Ridgebit's Thesis

by White_Eyebrow



Series: The Houses Competition: Year 5 [3]
Category: Harry Potter - J. K. Rowling
Genre: Aurors, Awkward Flirting, Duelling, F/M, Friendship, Mystery, Unicorns
Language: English
Status: Completed
Published: 2019-09-08
Updated: 2019-09-08
Packaged: 2021-01-29 12:28:08
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,806
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21410182
Author URL: https://archiveofourown.org/users/White_Eyebrow/pseuds/White_Eyebrow
Summary: Can Tonks and Charlie solve the mystery of Ridgebit's thesis... and survive?
Relationships: Nymphadora Tonks/Charlie Weasley
Series: The Houses Competition: Year 5 [3]
Series URL: https://archiveofourown.org/series/1543387
Kudos: 3





	1. SHHHH!

**Author's Note:**

> This story was written for The Houses Competition, Year 5, Round Deux.
> 
> House: Gryffindor (The only house that matters)  
Class Subject: Potions  
Category: Drabble  
Prompts:  
[Setting] Hogwarts Library  
[Weather] Hail  
[Emotion] Perplexed

Hail pummeling the castle made studying inside Hogwarts Library impossible for Charlie Weasley. During the worst of it, his brothers Percy and Bill took a break and relaxed with their respective periodicals while Charlie reclined with his textbook in his lap, staring at the ceiling.

It was easy for Nymphadora Tonks to approach Charlie unnoticed. She tapped his crown. "I thought I'd find you in the library... I'm calling in my marker, _Weasley." _(1)

Charlie rose from his chair, towering over the petite Hufflepuff. "That didn't take long; It hasn't even been a week."

At the mention of his surname, Bill, who had been sitting next to Charlie, folded his copy of _The Daily Prophet_, and regarded Tonks.

She straightened. "Oh, hello, William."

Bill smiled. "Hello, Nymphadora."

Charlie gasped. _Did he just call her...?_

Tonks leaned against Bill's desk, her dainty finger twirling a lock of her pink hair. "Sorry, I didn't see you there."

Charlie's book fell from his relaxed grip. It landed on his foot, snapping him out of his shock, and he quickly retrieved it for fear that Madam Pince might pounce. His gaze alternated between Tonks and Bill with a pinched brow. _Am I the only one that noticed…?_

Tonks glanced at the familiar headline of the article Bill had been reading:

"UNICORN BLACK MARKET RING BAFFLES MINISTRY"

"Terrible, that news about the unicorns, innit?" she said.

"Yes, Nymphadora, I hope the Aurors catch those responsible—"

"_SHHHH!"_ The cacophony of the hail's onslaught was not enough to defeat Madam Pince's trained ear.

Having had enough, Charlie took Tonks brusquely by her arm, causing her to involuntarily yelp, and led her to an out-of-the-way aisle, next to a window, against which the unrelenting hail afforded better acoustical concealment than any Silencing Spell.

Exasperated, Tonks said, "What's wrong?"

"You tell me, _Nymphadora."_

Tonks' glower gave him notice, underscored by her hair magically diffusing into a bright shade of crimson. "Don't. Call me. Nymphadora!"

He stepped back. "There it is: _the reddening_… even gets in your eyes, doesn't it...?"

"You _know_ that I don't like that word, Chuck."

"Then why does my elder brother get to call you That-which-makes-your-hair-turn-red?"

"He never called me anything of the sort."

Charlie blinked. "Really…? So, what did you hear exactly when he addressed you just now?"

Her stare went blank; she hugged her books to her breast, sighing with head cocked askew, and answered, "_Dearest…"_

He grimaced. "That word doesn't even _remotely_ sound like Nympha—er, that particular parlance that permanently pesters you…"

"Focus, Chuck." She blinked thrice, and the red disappeared from her eyes. "I require your expertise in dragonology."

He sniffed haughtily. "Continue."

"What do you know about _Ridgebit's thesis?"_

"A great deal," he said. "Why the sudden interest in dragons?"

"Ever since the story broke in the _Prophet_ regarding the influx of unicorn blood on the black market."

"That _is_ a mystery. The Aurors can't find where it's coming from—as no one has reported any dead unicorns—and there have been no sightings of 'half-lifers' walking around."(2)

"And that got me thinking… what if the unicorns aren't being slain?"

"That would affect their blood's healing power, but theoretically, neither would any suffer the dreadful side effects." He rubbed his chin. "Either way, you'd need more of it… like a drug."

She nodded. "If I were going to harvest unicorn blood, the herds that roam wild and unmonitored in the Forbidden Forest would be my first choice."

"But, Hagrid has spent the better part of a week trying to track the herds to no avail, and if _he_ can't find them, nobody can."

"What if Hagrid's been looking in the wrong place?"

"Why do you say that?"

"I was hoping you could tell _me,_ going back to _Ridgebit's thesis_."

"Of course…." In an inspired epiphany, he led her to the Dragon Section. With a flourish of his wand, a large book magically leapt from the shelf and landed on the table. Charlie opened it, showcasing a map of the Forbidden Forest. "Given that dragons are particularly fond of eating unicorns, Harvey Ridgebit asserted that unicorn migratory patterns are dependent upon dragon mating behaviour: they go into hiding during the seasons where dragons are most prolific, and they likewise breed to offset predation."

"If these multiple correlations can be used to predict dragon behaviour, will it work in the reverse?" she asked.

"Who knows?" He replied. "The dragon population in this region is nonexistent."

"But, the unicorns don't know that. They'll have continued to follow their instincts bred into them over generations, wouldn't they?"

"Let's examine that." His fingered stilled to the relevant area on the map. "Hagrid would be _here_ if he is following the yearly migration patterns of our unicorns." He then invoked the Summoning Spell; an almanac flew off the shelf and alit, opened thus, on the table next to the map. He pursed his lips as his eyes scrolled down the chart on the page, saying, "According to the Dragon Almanac, the females of the dragon breeds that were once native to this region ovulate every five years..."

Tonks leaned in, looking over his shoulder. "Would this year be such a year?"

He arched an eyebrow. "Yes... Not only that, we're right in the middle of their historic mating season."

"Unicorns are very intelligent," she said. "They have genetic memory."

He grinned. "I didn't know you were such a unicorn afficianado."

Tonks shrugged. "I inherited it from my mum; her patronus was a unicorn, as was her mum." (3)

Charlie returned to the map. "If _I_ were a unicorn, so aware, I would be as far away from my natural stomping grounds as possible..." His finger glided to the opposite side of the map. "Further taking the aforementioned into account, the herd should be situated _here."_ He snorted as he drew the obvious conclusion. "I believe you may be right…" He regarded her beaming eyes. "Brilliant!"

"It's about time you noticed." She smiled. "So, bring your map, and meet me in the second floor corridor at half past midnight—"

"Er, why?"

"Sneaking _out_ of the castle is easy, but I'm going to need a guide in the Forbidden Forest."

Charlie folded his arms. "Do you fancy yourself an Auror now?"

With her hands on her hips, she met his glare. "And what if I do?"

"We should inform the headmaster."

"Dumbledore will dismiss us without proof," she said. "We should confirm our theory first."

"And risk expulsion? I don't think so."

"But, you owe me, Chuck." She pouted, and her reddened hair reverted back to its usual gentle pink hue.

"I'm a prefect now, Tonks. I have to set an example."

Her eyes widened, and her head tilted as she hugged her chest. "_Pleeeease…"_

"That's _not_ going to work!"

She grabbed his arm, placing her head on his shoulder. "I'll be your best friend…"

He wagged his finger at her sternly. "There is no way you're going to talk me into going along with this rubbish scheme of yours!"

"_SHHHH!"_

The students quieted upon Madam Pince's stealthy arrival, and they averted their eyes under her disapproving frown.

This, however, did not stop Charlie from whispering to Tonks one last, "Never gonna happen..._"_

**Notes for the Chapter:**

> (1) from _The Rule Breakers_
> 
> (2) _Harry Potter and the Philosopher's Stone,_ chapter 15
> 
> (3) _Prisoner of Hope,_ chapters 6 & 10.


	2. Skullduggery

**Notes for the Chapter:**

> This story was written for The Houses Competition, Year 5, Round Deux.
> 
> House: Gryffindor (The only house that matters)  
Class Subject: Potions  
Category: Standard  
Prompts:  
[Spell] Arresto Momentum  
[Creature] Unicorn

Well after midnight Charlie Weasley knocked on the door to Hagrid's hut on the edge of the Forbidden Forest. There was no answer; the lights were off, and no signs of life were inside, so he mounted his conveyance and joined Tonks, who was waiting aloft on her broom.

Her robe flapped in the night breeze. "Well?"

Charlie shook his head. "Nobody's home. Hagrid must be camping out in the field."

She smirked knowingly. "We tried it your way, Chuck; shall we press on?"

He followed her along the periphery of the forest. It didn't take them long to reach the densest part, where the foliage obscured direct observation from the air. They found a convenient place to land, and stowed their brooms inside Tonks' handbag that had been imbued with the Undetectable Extension Charm, as it was more practical to leg it at this point.

Their wands illuminated the path; nary a single ray of moonlight could penetrate the dense brush. As a result, they had to pause periodically to allow Charlie to renew their bearings using his map.

Patience in this regard was not one of Tonks' virtues. "Are we there yet?"

"No."

She spun behind them. "Did you hear that?"

"Of course," Charlie said plainly. "It's a forest… it's full of things that're going to make noise." He continued on.

Her wand light revealed nothing but branches swaying in the wind. Satisfied, she caught up to Charlie. "You'll have to forgive me… I'm an indoor cat."

She looked warily over her shoulder and almost tripped over a rock, cursing.

He did not break stride. "You certainly lack a cat's reflexes."

"I keep hearing something… like we're being followed."

"Maybe you shouldn't make so much noise," he teased. "Aurors are supposed to be stealthy, aren't they?"

"You get crabby without your beauty sleep, don't you?" Tonks said, as Charlie's dismissiveness had worn thin. "How do you know we're going in the right direction, anyway? I'm starting to have doubts about this Ridgebit bloke."

"I'm going to pretend I didn't hear that," he replied. "It was Ridgebit's idea to leverage unicorn herd psychology to infer when Dragon mating season occurs. He used the technique to capture a live Peruvian Vipertooth. I never would've thought you could infer the reverse to find a herd of rogue unicorns."

She snorted. "Apparently, neither did Hagrid."

"Agreed... not bad for an indoor cat—"

They suddenly stilled, an odd sound in the distance having given them pause.

Tonks scanned the darkness to no avail. "Tell me you heard that!"

"I did." He brought his wand to the ready.

Tonks reached into her handbag and pulled something out. "Do you think you can cast that same Confundus Charm you used on your faux dragon egg in order to conceal _this?" _(4)

Charlie regarded the proffered object; it made him frown. "A Snargaluff pod? Those are dangerous."

"Not when you have it suspended within a Stasis Charm." She grinned. "An Auror is always prepared, Chuck."

Charlie enchanted the object, giving it the appearance of a Quaffle. Tonks set it down, and from a safe distance she activated the pod. They hid behind a nearby bush and waited.

It wasn't long before a tall dark figure came upon the scene. Obscured in shadow, he had an odd gait as his heavy footfalls made a distinctive sound against the cold, hard ground.

_Clomp… Clomp… Clomp… Clomp..._

The ominous figure knelt to examine the false object, and when he touched it, the trap was sprung. "BLOODY HELL!"

The students came out of hiding, their wands at the ready as they approached the intruder who had become thoroughly ensnared within the plant's tentacles.

Tonks' wand glowed. "Wotcher, tosser!" And she conjured a flash of light to get a better look at the intruder who continued to struggle in his bindings.

The students gasped at this scarred ogre of a man with grey grizzled hair, with one normal eye at the youths he did glare. The other—overlarge for its orb, fitted overtight, flitted to-and-fro—was a truly garish sight.

The old man almost growled when he spoke. "When I get my hands on you two, there'll be hell to pay!"

Tonks screamed. She ran with Charlie close behind. She stumbled along the way. Charlie helped her up, and they retreated to an open clearing far off the beaten path.

She rested with her hands propped on her knees. "Did you see his face, Chuck? Was he even human?"

"I don't intend to go back and ask. In either event, he won't be giving us any more problems this night."

She looked about. "Where are we?"

"I don't know." Charlie brandished his wand. "_Lumos."_

They regarded a wall of vegetation that swayed rhythmically, yet there was no breeze. Tonks knelt at the base of the wall, examining a patch of green via wand light. "Devil's Snare interwoven with Venomous Tentacula… they don't normally play nice together."

"They appear to form a perimeter," Charlie said. "This is not a natural formation." He walked parallel along the boundary, mindful not to venture too close. "Is it part of some sort of defense, you think? To keep intruders out?" he questioned.

Tonks had a different opinion. "Or, a corral, to keep something _in."_

They shared a knowing smile, and they pointed their wands, casting the Pruning Charm. The magic did its job, and they ventured past the deadly hedge.

They paused once they crossed the threshold. An inlet in the canopy allowed the moonlight to illuminate a small glen centered about a mighty tree that served as a home for two dozen unicorns. They grazed lazily under the silver moonlight.

Overcome with emotion, Tonks' eyes welled. Charlie put his arm across her slight shoulders and pulled her close.

"Congratulations," he said. "You've turned _Ridgebit's thesis_ into _Ridgebit's theorem."_

They approached the nearest unicorn, a mare nursing a foal, but stopped when a stallion came upon them.

The stallion stood on his hindquarters and put on an aggressive display, stamping its forelimbs on the ground. He bared his horn down on the humans.

When the beast charged, Charlie aimed his wand, invoking, "_Arresto Momentum!"_ And the unicorn's advanced slowed as if he were wading through a pool of molasses.

"Don't hurt him!" Tonks said. "He's just scared."

"_He's_ scared…?!"

Tonks' hair turned silver and lengthened into a mane; the rest of her body followed suit as she transformed into a unicorn mare. She slowly approached the stallion and allowed him to smell her; this seemed to calm the beast. She transformed back into a human, and the stallion allowed her to stroke his mane. When it was safe, she motioned for Charlie to approach; he likewise petted the animal.

He ran his palm across the many wounds along the animal's body. "He's been hurt… these cuts look surgical."

"They're bleeding them like vampire bats," Tonks said; looking about, she saw that other members of the herd were scarred in a similar fashion. "What kind of monsters would do this to defenseless animals?"

"Seeing as how you placated this alpha stallion, we can use him to lead the rest of the herd out of here."

The stallion neighed, spooked by something, and it trotted off. The entire herd now seemed on edge.

Charlie's brow furrowed. "What's wrong with them?"

She shrugged. "I don't speak unicorn—"

_BAM!_

_BAM!_

_BAM!_

_BAM!_

Four Dark Wizards Apparated onto the scene, brandishing their wands, making Tonks and Charlie give a start. Their backs to the moonlight, it was impossible to make out their faces in the darkness.

The leader's fine linen robes set him apart from the others. "What do we have here?"

"Well, guv'nor, looks like you're not the only one who was able to track the beasts, yeah? I thought you said this place would be secure on account of that dragon bloke you told us about...?"

"Ridgebit." The leader answered. "They're just kids… blind luck, it is."

"Kid's, are we?" Tonks clenched her teeth, and her hair turned bright crimson in her retroactive outrage. "What does that say about _you,_ if a couple of 'kids' sussed your skullduggery!"

"Tonks, how about we _not_ provoke the Dark Wizards, yeah?" Charlie's plea came too late.

"A Metamorphmagus, she is!"

"She could fetch us a mint on the continent."

Charlie levelled his wand at the shadowed figures. "You're not taking her, anywhere!"

"And who's going to stop us, boy? There's four of us, and only two of you."

"Their 'two' barely counts as 'one'."

The Dark Wizards laughed.

"Enough," their leader said. "Disarm them."

Tonks and Charlie formed up as their enemies primed their wands. Her hand found his, and their fingers interlaced; with wands held to the fore, in unison, they spake, "_Expelliarmus!"_

The herd bolted at the blinding influx of light as magic clashed against magic.

The students held their ground, but being outnumbered, it wasn't long before the duel was lost. A curse caused Tonks to fall, her legs made useless. A Knockback Jinx likewise hit Charlie in the chest, sending him flying several feet and knocking the wind out of him. He lost his wand.

The burly wizard approached Tonks as she struggled to sit upright. "We're going to have _so_ much fun, girlie." He sheathed his wand, knealt before her and ran his fingers through her crimson locks.

She averted her eyes at his touch, her bottom lip trembling.

Though weakened, Charlie managed to his feet and charged. "GET YOUR HANDS OFF OF HER, NOW!" However, the brawny wizard rose to meet him and caught him mid-tackle.

He threw the boy off. "We have a tough guy here, fellas." He clasped his hands behind his back, towering over the youth. "I'm the sporting sort, so I'll let you have the first punch, lad… After that, it's game on!" With a leer the henchman leaned in—his eyes closed—he stuck out his chin.

Charlie clenched his fists, ready to swing, but he stilled when he heard a familiar sound behind him.

_clomp… clomp… clomp… clomp..._

Something unseen brushed past Charlie, shoving him aside, and he stumbled, landing on his back. He blinked, nonplussed, as something, or someone, tossed him his wand, landing it on his chest.

The invisible entity threw off his magic cloak—the old man with the mad eye—"Much obliged"—and he punched the big man, caught unawares, across his jaw, knocking him out.

The dark leader scowled. "TAKE HIM DOWN!"

"_Mobilicorpus!" _The old man levitated the prostrated Dark Wizard and used him as a shield. The unconscious body, pelted by curses, bucked and twitched like a marionette under the palsied hands of a puppeteer with Parkinson's. He stepped off the line with his wand primed. "_Stupefy! Stupefy!" _And the last two henchmen were felled.

Charlie was already at Tonks' side while the old man and the Dark Wizard leader were locked in a deadly duel. He picked her up, as her legs were still useless, and made a break for the way out. The air tasted coppery.

"Wait," she pleaded. "We can't leave the unicorns behind!"

"You are more important to me than the blasted unicorns!"

"Please, Chuck!"

He curled his lip. _Crap!_ And he relented. He set Tonks down and pointed his wand skyward.

A roar shook the leaves of the surrounding trees.

"What was that!" Tonks said.

"I'm simulating the mating call of a Hungarian Horntail."

She perceived his strategy, using the mating call to corral and steer the stampeding unicorns toward the threshold of the twained hedge.

However, a flaw in the plan became apparent as they were situated between the stampede and the exit. Tonks retrieved a broom from their provisions; however, seeing as how her legs weren't working, Charlie held her with one arm as he steadied them on his broom. The broom struggled under their combined weight, but it managed to float them skyward, allowing the herd to safely pass under them. Tonks used the opportunity to cast a second pruning spell to widen the gap in the hedge, and the unicorns knew freedom.

The duo cleared the treeline and flew toward the castle.

—oOo—

Charlie woke up too late for breakfast, but was content relaxing in the Hogwarts courtyard on a lazy Saturday afternoon. He sat at the base of the largest tree. The sun was warm, and the pleasant breeze began to lull him to sleep. He allowed himself to drift, until Tonks' abrasive voice roused him.

"Wotcher, Chuck!" She tossed the latest copy of the _Prophet_ onto his lap and commanded, "Read it."

She sat next to him as Charlie unfolded the newspaper. He skimmed the headline. "So, the Aurors brought the black market traders to heel… But, we already knew that, didn't we?"

"Yes, but they made no mention of the part you and I played in the coppering!"

"Probably because our part was extraordinarily nominal," he said. He reclined his head against the tree and closed his eyes. "I'm just happy we got out alive." He started to drift again.

She waited until he was completely relaxed, smirking as her finger twirled a lock of her pink hair. "Chucky…?"

"Yes, Tonks?"

"Did you mean it when you said that I am more important to you than all the unicorns?"

He straightened. "Er… I don't recall saying 'all'—"

"I'm sure you said _all."_

"Well… It is, after all, part of my job as a prefect to care for _all_ of my fellow students, innit?" He slumped; his eyelids grew heavy.

She leaned in closer. "_Chuuuckyyy…?"_

"Yes, Tonks?"

"Am I more important to you than _all_ the dragons?"

"All the dragons of which species?"

She frowned and folded her arms, giving a disapproving, "_Hmph!"_

Charlie grinned in satisfaction, and he yawned, when those familiar footfalls made him bolt upright.

_CLOMP… CLOMP… CLOMP… CLOMP..._

Tonks likewise gasped.

The youths rose to their feet as the old man from the Forbidden Forest approached them. Though his limp was more pronounced, he was even more intimidating in the daylight.

He regarded the boy first. His magic eye, moving in unison with his native eye, seemed less garish. "You're a Weasley?"

"Y-yes, sir."

"Your father's a good man." He then turned his attention toward the girl, saying, "You're a Black—"

She found her courage. "No… I'm a Tonks!"

The old man grunted and pursed his lips. He reached into his jacket and retrieved the Snargaluff pod from last night. "You should return this to the greenhouse while Professor Sprout is still none the wiser." He handed her the dormant plant. "Remember, an Auror always covers his tracks and stays constantly vigilant."

Tonks smiled.

The old man left without ceremony.

Tonks stashed the pod inside her robe. She regarded Charlie. "I told you I could be an Auror."

"I never said you couldn't."

She sighed. "I like that: _constant vigilance…_ it pops."

"He never said, 'constant vigilance.'" Charlie narrowed his eyes. "You have a selective hearing problem, you know that?"

She ignored him. "Now, I'm going to have to devise a plan to sneak this back into Professor Sprout's greenhouse." She grabbed his arm, and they walked toward the main entrance. "Meet me behind the grand staircase after lights out."

"Don't even think about it, Tonks!"

"You heard what the scary codger said about covering our tracks, didn't you?"

Charlie wagged his finger at her sternly. "There is no way you're going to talk me into going along with yet _another_ rubbish scheme of yours!"

"But, Chucky—"

"No—"

"_Pleeeease...?"_

"_No!"_

"I'll be your best friend…."

"Never gonna happen!"

**Notes for the Chapter:**

> (4) as he did in _The Rule Breakers_


End file.
